Question 18 RVR01 - Master of Unlimited Tonnage

The Correct Answer is A **Explanation for A (One prolonged blast):** The sound signal of "One prolonged blast" is internationally recognized under the COLREGs (International Regulations for Preventing Collisions at Sea) and domestically under the Inland Rules for warning or signaling intent when navigating situations of reduced visibility or potential danger. Specifically, both the International (Rule 34(e)) and Inland (Rule 34(e)) Steering and Sailing Rules require a power-driven vessel nearing a bend or an area where other vessels may be obscured (such as high banks or large structures) to sound **one prolonged blast** to alert any approaching vessel. If a responding vessel is heard, that vessel must answer with one prolonged blast. **Explanation for Incorrect Options:** * **B) Two short blasts:** This signal indicates a change of course to the port (left) side according to the International Rules (COLREGs Rule 34(a)(ii)) or indicates intentions when meeting, crossing, or overtaking according to the Inland Rules, but it is not the required signal for approaching an obscured bend. * **C) One short blast:** This signal indicates a change of course to the starboard (right) side (COLREGs Rule 34(a)(i)) or indicates intentions when meeting, crossing, or overtaking according to the Inland Rules. It is a signal of maneuvering intent, not a required warning signal for an obscured bend. * **D) One long blast:** While the term "long" and "prolonged" are often used interchangeably in general conversation, in the context of navigation rules, the specific technical term for the required warning signal at a bend is "prolonged blast" (defined as 4 to 6 seconds in duration). Choosing "prolonged" (Option A) is the most accurate regulatory term compared to the generic "long," although "long" is sometimes used loosely in informal contexts.